1. Field of the Invention
The present invention relates to a distance measuring apparatus, and more particular to an active distance measuring apparatus used in cameras etc.
2. Related Background Art
Conventional active distance measuring apparatus for normal cameras are arranged to have an infrared light-emitting diode (hereinafter referred to as "IRED") and a position sensing device (hereinafter referred to as "PSD") for receiving infrared light emitted from the IRED and then reflected by an object, and are constructed in such an arrangement that signal currents output from the PSD are subjected to arithmetic processing in a signal processing circuit and an arithmetic circuit to obtain an output of distance information and that a microcomputer (hereinafter referred to as "CPU") detects a distance from the distance information.
Since an error could result from distance measurement with single emission of infrared light, a plurality of emissions, for example 256 emissions, are normally performed to obtain a plurality of distance data and then to integrate the plurality of distance data. Thus, the conventional distance measuring apparatus are normally provided with an integration circuit for integrating output signals from the arithmetic circuit.